Morphological Chart
The following shows how the concepts were arrived upon. At first, the device was to be purely mechanical. Hence, for each of the functions the device was to perform, different methods for it to perform this function are shown. This allowed us to combine one possible option from each row to attain one design option. This lead to the four options shown below.
IUD (Individual Unit Dose) Pill Strip
The actual CoumadinÒ Pills are inside each of the perforated IUD pouches. The above picture has 23 pouches, which come together as an accordion. This allows for easy storage of the pills inside our device. This is the reason this pill packaging was utilized, along with the protection it offers the pill against humidity.
The resulting concepts using the above morphological chart. These designs were considered until the customer specifications changed and a motor was included.
However, when the design needs changed and our client decided a motor was convenient, the following designs were considered. Both designs look similar, but the onw on the right (wormset) proved to be the better option. This due to the self locking mechanism inherent with this option. This would help with our design, since when the motor stops, the top knurled wheels should stay immobile. The principle behind this design is the motor rotates the worm, which then rotates the worm gear. This, in turn, rotates the spur gears (shown on the side), which then rotates the knurled rollers. These rollers have an impressed pattern on them to increase the friction. The pill strip will be dispensed perpendicular to the page towards away from the screen. When one pill has been dispensed, the patient will then tear; hence the importance of having pressed knurled rollers.
A wormset is shown below. The worm can drive the worm gear; however, the worm gear cannot drive the worm. This, along with the pressure angle properties, allows for the self-locking properties of the worm. This is a major advantage of the design.
